Core C will serve as a centralized unit for providing the requisite expertise, personnel, and equipment to support all projects in the Program Project. Each of the four projects explores the shared theme of neutrophil (PMN)-mediated lung vascular injury and so will draw heavily on the services offered by Core C. The majority of Core C services are structured around the perfused mouse lung preparation developed by the core leader and other investigators in the program during the past 5 years to take advantage of the availability of various murine transgenic and knockout models. The following physiological assessments will be made to characterize in vivo injury of the lung vessels: 1) transvascular protein and liquid permeability and rate of edema formation, 2) oxidant production, 3) lung tissue NF-KB activation and ICAM-1 expression, and 4) uptake of 111ln-oxine-labeled mouse PMN. To complement these assessments, Core C will also supply relevant imaging services such as fluorescent staining of lung microvessels. In addition, the assay of PMN uptake by stereology will provide specific quantification of vascular, interstitial, and alveolar PMNs in lungs. Core C also will furnish investigators with an in vitro assay for endothelial protein permeability with the aid of albumin tracers in mouse lung primary endothelial cell monolayers. A pivotal service to project P.I.s will be the transient transfection of lung vessels with liposome-delivered cDNA, and evaluation of the resulting protein expression by fluorescent microscopy. The physiological assessment of the mouse lung is vital to successful execution of specific aims in Projects 1,3, and 4, and specific aims in Project 1 call for transient transfections of lung vessels. Some aspects of Projects 2 and 4 will require an in vitro assay of transendothelial albumin permeability. As the services available through Core C are specialialized and require personnel with extensive training and experience, the centralized activity of Core C is essential for cost-effective and efficient completion of the experiments in all projects and hence for the overall success of the Program Project.